Method of manufacturing a press felt, and a press felt, with the shape of a closed loop

ABSTRACT

The invention relates to a method of manufacturing a press felt and to a press felt and a base fabric. The base fabric comprises at least a first planar compo-nent ( 4 ), which includes a first transverse (CMD) joining edge area ( 11 ) and a second transverse joining edge area ( 12 ). The joining edge areas ( 11, 12 ) are arranged to overlap each other and attached to each other undetachably.

BACKGROUND OF THE INVENTION

The invention relates to a method of manufacturing a press felt, themethod comprising at least the following steps of: forming a base fabricwhose at least one layer comprises at least a first planar component,which is formed from a plurality of longitudinal yarns that travel inthe machine direction and transverse yarns that travel in the crossmachine direction, and providing the first component with a firsttransverse joining edge area and a second transverse joining edge area;arranging the first and the second transverse joining edge area of thefirst component so that they overlap each other; and forming a basefabric with the shape of a closed loop; and attaching at least one battfibre layer to the base fabric with the shape of a closed loop; and themethod comprising attaching the joining edge areas to each otherundetachably before the attachment of the batt fibre layer.

The invention further relates to a press felt for a paper machine presssection, the press felt comprising: a base fabric, which includes aplurality of longitudinal yarns that travel in the machine direction anda plurality of transverse yarns that travel in the cross machinedirection and whose at least one layer is provided with at least a firstplanar component, which includes a first transverse joining edge areaand a second transverse joining edge area and where the joining edgeareas are connected to each other, and at least one batt fibre layer,and where the first and the second joining edge area of the firstcomponent are arranged so that they overlap each other, and where thejoining edge areas are attached to each other undetachably before theattachment of the batt fibre layer.

The invention further relates to a base fabric for a press felt,comprising: a plurality of longitudinal yarns that travel in the machinedirection; a plurality of transverse yarns that travel in the crossmachine direction; at least a first planar component in at least onebase fabric layer, and the first component includes at least a firsttransverse joining edge area and a second transverse joining edge area,and where the joining edge areas are connected to each other, and thefirst and the second joining edge area of the first component arearranged to overlap each other; and the joining edge areas are attachedto each other undetachebly.

Depending on the press structure, the press section of the paper machineemploys a press felt on one or both sides of the web to be dried, intowhich the water in the web may be absorbed in the pressing phase. Thepurpose of the press felt is to transport the water away in itsstructure without letting it back into the web. In the actual pressing,the paper web is conveyed on the felt into an opening between twocylinders, i.e. into a nip. The structure of the felt should allow goodabsorption of water into the felt in the nip. Press felts include a basefabric which, for example, provides the felt with a necessary space forwater. To obtain a smooth felt surface, batt fibre is attached at leastonto the base fabric surface facing the web. The base fabric istypically manufactured by weaving. The base fabric may be directly woveninto an endless loop. In that case, however, the width of the weavingmachine restricts the length of the base fabric to be manufactured. Inaddition, the fabric may be woven as a plane. This enables manufacturingbase fabrics provided with seam loops. By connecting the joining ends ofthe base fabrics, a base fabric with the shape of an endless loop can beformed. The seam loops may, however, cause markings on the web to bedried. In addition, adherence of batt fibre to the area provided withseam loops may also pose a problem.

BRIEF DESCRIPTION OF THE INVENTION

The object of the invention is to provide a novel and improved method ofmanufacturing a press felt, press felt and base fabric for a press felt.

The method according to the invention is characterized by pressing thejoining edge areas of the first component against each other during theattachment by a predetermined force so that the thickness of theoverlapping joining edge areas substantially corresponds to thethickness of the rest of the first component.

The press felt according to the invention is characterized in that thejoining edge areas of the first component have been pressed against eachother and that the thickness of the overlapping joining edge areassubstantially corresponds to the thickness of the rest of the firstcomponent.

The base fabric according to the invention is characterized in that thejoining edge areas of the first component have been pressed against eachother and that the thickness of the overlapping joining edge areassubstantially corresponds to the thickness of the rest of the firstcomponent.

The invention is based on the idea that the base fabric comprises atleast one planar component provided with a first transverse joining edgearea and a second transverse joining edge area. The joining edge areasare arranged to overlap each other, after which they are attached toeach other undetachably. Such an overlapping joint makes seam loops andother similar joining members unnecessary.

An advantage of the invention is that it facilitates and speeds up themanufacture of a planar component since the component needs not beprovided with seam loops in the weaving machine. Since seam loops arenot needed to connect the joining edges, the joining edges can be formedanywhere in the planar component. The seam loops, however, have to beformed already in connection with weaving. In addition, the jointaccording to the invention provides a good base to which batt fibre canbe attached. The joint is also firm and quick to manufacture. It isrelatively easy to automate the implementation of the joint.

A preferred embodiment of the invention is based on the idea that atleast one joining edge area of the planar component is provided with athinned portion, where the density of transverse yarns is smaller in apredetermined section starting from the end of the component than in therest of the component. Thanks to the thinning, the thickness of theoverlapping joint can be decreased so that it does not significantlydiffer from the rest of the component structure. The thinning alsoaffects the permeability of the overlapping joint so that it does notsignificantly differ from the rest of the component structure.

A preferred embodiment of the invention is based on the idea thatthinning is implemented by removing several transverse yarns from thejoining edge area after the manufacture of the component.

A preferred embodiment of the invention is based on the idea that asmaller number of transverse yarns are arranged in the joining edgeareas than in the rest of the component during the manufacture of theplanar component.

A preferred embodiment of the invention is based on the idea that theoverlapping joining edge areas are attached to each other by welding.

A preferred embodiment of the invention is based on the idea that atleast the portion with overlapping joining edge areas is provided withan attachment area, where the joining edge areas have been attached toeach other undetachably. In addition, the boundary surface between theattachment area and the rest of the first component is made non-linear.Since the boundary surface is not clearly distinguishable, markings canbe prevented.

A preferred embodiment of the invention is based on the idea that atleast the portion with overlapping joining edge areas is provided withan attachment area, where the joining edge areas have been attached toeach other undetachably, and the attachment area is provided withseveral attachment points, which form a pattern that imitates thepattern on the base fabric surface. This way markings can be avoided.Furthermore, thanks to the attachment points, permeability in theattachment area may substantially correspond to that in the rest of thebase fabric.

BRIEF DESCRIPTION OF FIGURES

The invention will be described in greater detail in the accompanyingdrawings, in which

FIG. 1 illustrates a schematic cross-section of a press felt accordingto the invention in the paper machine direction MD,

FIG. 2 is a schematic perspective view of a base fabric according to theinvention,

FIGS. 3 to 5 schematically illustrate an alternative of forming a basefabric according to the invention,

FIGS. 6 to 8 schematically illustrate a way of forming a transverse seamfor the base fabric component according to the invention as across-section in the machine direction MD,

FIG. 9 is a schematic top view of the seam according to FIG. 8,

FIGS. 10 and 11 are schematic top views of a second way of forming aseam according to the invention,

FIGS. 12 and 13 are schematic top views of a third way of forming a seamaccording to the invention,

FIGS. 14 to 16 are schematic top views of feasible shapes for anattachment area,

FIGS. 17 and 18 are schematic top views of feasible shapes for a weldingmark, and

FIG. 19 schematically illustrates yet another way of forming a basefabric.

For the sake of clarity, the figures illustrate the invention in asimplified manner. Like reference numbers refer to like parts in thefigures.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a press felt according to the invention as a sectionin the paper machine direction MD. The felt illustrated in the figurecomprises four layers attached to one another. On the felt surface Afacing the web, there is a first batt fibre layer 1 as the outermostlayer. Below the first batt fibre layer, there is a base fabric 2consisting of two components, and further at the bottom of the felt,i.e. on the surface B facing the paper machine, there is a second battfibre layer 3. The first batt fibre layer 1 prevents the generation ofmarkings, i.e. a pattern caused by the weave of the base fabric, ontothe web surface. In addition, water retention properties of the felt canalso be affected by batt fibre. The first batt fibre layer 1 may consistof two or more thin layers, in which case there may be finer batt fibreon the surface of the batt fibre layer 1 and coarser batt fibre belowit. The second batt fibre layer 3 at the bottom of the felt is notnecessary.

The base fabric 2 may comprise one or more superimposed components 4 and5. The components 4 and 5 may be woven in different phases and arrangedone on top of the other before the batt fibre layers 1, 3 are attached.The base fabric 2 according to FIG. 1 comprises a one-layer surfacecomponent 4 and a two-layer bottom component 5. Thus the base fabric 2has a laminate structure. It should, however, be noted that the basefabric 2 may consist of only one component, or on the other hand, theremay be more than two superimposed components. The first component 4 inthe base fabric is woven from longitudinal yarns 6 that travel in themachine direction MD and transverse yarns 7 that travel in the crossmachine direction CMD using a suitable weave. Correspondingly, thesecond component 5 is woven from longitudinal yarns 8 that travel in themachine direction MD and transverse yarns 9 that travel in the crossmachine direction CMD. For the sake of clarity, the figure illustratesonly some of the yarns belonging to the layers. In the solutionaccording to FIG. 1, yarns 6, 7 and 8 are monofilaments and yarns 9 areplied monofilaments. The structure and material may be selected for theyarns on the case-by-case basis. Thus they may be monofilaments, pliedmonofilaments or multifilaments. The yarns may be made of a suitableplastic material, such as polyamide (PA).

FIG. 2 illustrates a base fabric 2 with the shape of a closed loop. Asappears from the figure, the base fabric 2 includes a seam area 10 inthe cross machine direction CMD that connects the first transversejoining edge area 11 and the second transverse joining edge area 12 ofthe base fabric 2 to each other. At least one layer of the base fabricmay be formed from several planar components connected to each other'sextensions, in which case there are several transverse seam areas 10.After the base fabric 2 with the shape of a closed loop has been formed,it may be treated thermally and the batt fibre layers intended for itcan be attached by needling, for instance. Alternatively, the basefabric 2 components may be treated with heat before the assembly. Theattachment of batt fibre may increase the strength of the seam area 10.

FIGS. 3 to 5 illustrate one way of forming the base fabric 2. FIG. 3illustrates the second base fabric 2 component 5, which is manufacturedas an element with the shape of a closed loop. FIG. 4 illustrates thefirst base fabric 2 component 4, which has been shaped into a planarelement, whose width substantially corresponds to the width of the pressfelt and which comprises a first joining edge area 11 and a secondjoining edge area 12. The components 4 and 5 may have been manufacturedby weaving in separate phases. The base fabric 2 is assembled byarranging the first planar component 4 on top of the second component 5with the shape of a closed loop. The joining edge areas 11 and 12 of thefirst component 4 are arranged to overlap over a certain predetermineddistance, after which they are attached to each other. The attachmentcan be implemented by adhesive, by needling, by melting or by welding.The structure of the joining edge areas 11 and 12 may correspond to therest of the component 4 structure or they may have a thinner structure,as will later appear from FIGS. 7 to 13. In addition, the joining edgeareas 11 and 12 may also be attached to the second component 5.

An advantage of the structure shown in FIG. 5 is that the uniform secondcomponent 5 sustains well the forces to which it is subjected in themachine direction MD during the run. In that case, the seam area 10 inthe first component 4 does not necessarily need to sustain the forcesgenerated in the machine direction MD during the operation, but it issufficient that it sustains the mechanical stresses generated in themanufacturing process, thus facilitating the handling of the base fabric2. The other properties of the base fabric 2, such as density andsurface properties, can be affected by the first component 4. The firstplanar component 4 is easier to manufacture than a loop-shapedcomponent. In addition, there are several alternatives for selecting thestructure and properties for the planar component 4.

FIGS. 6 to 8 illustrate one way of forming a transverse CMD seam area10. FIG. 6 illustrates the first joining edge area 11 and the secondjoining edge area 12 of the planar component 4. As appears from Figure7, transverse yarns 7′ can be removed from a portion L of the secondjoining edge area 12 corresponding to the width L of the seam area 10starting from the end of the joining edge area 12. The number of yarns7′ to be removed may be 1 to 10, for instance. The number of the yarns7′ to be removed depends, for example, on the yarn thickness and theweave of the component 4. The length of portion L may vary between 2 and100 mm. Preferably, the length of portion L is between 5 and 20 mm. Thejoining edge area 12 from which yarns have been removed comprises onlylongitudinal yarns 6. After this, the second joining edge area 12 can bearranged to overlap the first joining edge area 11 as shown in FIG. 8 indirection H, which is transverse to the component 4 surface. After this,the joining edge areas 11 and 12 can be attached to each other. Theattachment can be performed by ultrasonic welding. During the welding,the joining edge areas 11 and 12 can be pressed against each otherbetween opposing surfaces 13 and 14 included in the welding device. Thewelding device may include discoid opposing surfaces 13, 14, which canbe rolled in the transverse CMD direction during the welding.Alternatively, the opposing surfaces can be moved step by step. Theshape of the opposing surfaces can be selected on the case-by-case basisso as to obtain different seam shapes as shown in FIGS. 14 to 18. Forthe sake of clarity, the opposing surfaces are shown at a distance fromsurfaces A and B of the component in FIG. 8. The press force F can bedetermined such that the component 4 is at least slightly compressed inthe seam area 10, in which case the seam area thickness G does notsubstantially differ from the thickness of the other parts in thecomponent 4. Furthermore, compression contributes to the attachment ofthe welded parts to each other. Compression can also be employed inother welding and attachment techniques. One feasible alternative is tocompress at least one joining edge area 11, 12 in advance before theareas are superimposed.

FIG. 9 is a top view of the seam area 9. For the sake of clarity, thesecond joining edge area 12 of the component 4 is illustrated withthicker lines in FIGS. 9 to 13. The width of the seam area 10 ispreferably between 5 and 20 mm.

FIG. 10 illustrates a solution where both the first joining edge area 11and the second joining edge area 12 of the component 4 have been thinnedby removing transverse yarns 7 from them. Yarns 7 may preferably beremoved from a portion of about 5 to 20 mm. After this, the joining edgeareas 11 and 12 are arranged to overlap as shown in FIG. 11, in whichcase the longitudinal yarns of the first joining edge area 11 and thesecond joining edge area 12 are next to each other or one on top of theother in the seam area 10. After this, the joining edge areas 11 and 12are attached to each other undetachably. The joining edge areas 11, 12may be have an equal length, but in some cases they may be of differentlengths.

FIG. 12 illustrates a further way of forming thinned joining edge areas11 and 12 for the overlapping joint of the invention. Alternatively,only one joining edge area 11, 12 is thinned. The thinning may beimplemented by weaving transverse yarns less densely in the joining edgeareas 11, 12 than in the other parts of component 4. The density oftransverse yarns in the joining edge area 11, 12 may be 50 yarns/10 cm,and in the other parts of the component 4 the density may be 100yarns/10 cm, for instance. In some cases the density of transverse yarnsmay gradually increase starting from the end of the component, finallycorresponding to the rest of the component structure. FIG. 13illustrates the situation after the joining edge areas 11, 12 have beenarranged to overlap.

FIGS. 14 to 16 illustrate some shapes of the attachment area 15. Theattachment area 15 refers to the portion at and around the seam area 10where the joining edge areas 11, 12 have been attached to each other.Various welding techniques may be employed in the attachment, such asultrasonic welding, laser welding, high-frequency welding, hot wedgewelding, fusion welding or any other welding method suitable for joiningyarns that are at least mainly made of plastic material. In addition,the attachment may be implemented by sewing or using an adhesive, forinstance. The boundary surface 16 between the attachment area 15 and therest of the component can be rendered less distinguishable from thestructure by selecting a suitable shape for the attachment area 15. Theboundary surface 16 may be linear as shown in FIG. 14 or non-linear asshown in FIGS. 15 and 16. In FIG. 15, the boundary surface 16 isserrated and FIG. 16 shows a boundary surface 16 with a random shape.

The attachment may be performed substantially over the whole attachmentarea 15, as illustrated in FIG. 17. Alternatively, particularly when awelding technique is employed, the attachment area 15 may be providedwith spotlike attachment points 17 or spotlike or continuous attachmentpoints 18 with a desired shape. It is further feasible to uselattice-shaped attachment points 19, in which case the pattern of thewelding seam may substantially correspond to the weave pattern. In thatcase, the welding seam is not distinguishable from the rest of thestructure. The attachment points may be formed such that their number,shape, size or other properties vary in the attachment area 15. Thus theattachment points may vary slidingly, in which case the attachment area15 cannot be distinguished easily. In addition, the attachment pointsmay be designed so that the permeability in the attachment area 15 doesnot substantially differ from that in the rest of the componentstructure. When batt fibre is needled, openings that affect permeabilityare formed in the attachment area.

Furthermore, attachment may have been performed only at the boundarysurfaces 16. The shape of the boundary surface 16 can be selectedaccording to the situation.

When the attachment is implemented by a welding technique, one or moreadditional yarns can be brought to the attachment area 15, if necessary,or other additional material, such as material that melts at a lowertemperature or additional material that improves the absorption of laserwelding.

FIG. 19 illustrates a yet another alternative for forming the basefabric 2. The first planar component 4 is arranged on one surface of thesecond component 5, in this case on top of the component. The firstjoining edge area 11 and the second joining edge area 12 aresuperimposed but are not attached to each other before the attachment ofbatt fibre. Instead, the first joining edge area 11 is attached to thesecond component 5 at the attachment area 15 undetachably using anattachment method described in this application, for instance. On theother hand, the second joining edge area 12 is not necessarily attachedat all but it forms a kind of seam flap 20 in the seam area 10. In somecases, however, the attachment can be performed at points 21 and 22.Even though only one joining edge area 11 had been attached, this wouldclearly facilitate the handling of the base fabric 2. An overlappingjoint with superimposed joining edge areas 11 and 12 is also anessential feature in this embodiment. The second component 5 may havebeen woven in the form of a closed loop. Alternatively, the secondcomponent 5 may have been formed from one or more planar components byweaving, for example. In that case, the planar component is connectedinto a closed loop by an overlapping joint or suitable joining members.

It is further feasible to provide the planar element 4 with joining edgeareas 11, 12 where transverse yarns 7′ differ from the transverse yarns7 in the other portions of the component 4. The joining edge areas 11,12 may comprise transverse yarns with different dimensions, materialsand structures.

The above-mentioned solutions may also be combined to form joining edgeareas.

The drawings and the related description are only intended to illustratethe inventive concept. The details of the invention may vary within thescope of the claims.

1. A method of manufacturing a press felt, the method comprising:forming a base fabric comprising at least one layer, wherein the atleast one layer comprises at least a first planar component, which isformed from a plurality of longitudinal yarns that travel in the machinedirection and from transverse yarns that travel in the cross machinedirection, and the first component is provided with a first transversejoining edge area and a second transverse joining edge area, arrangingthe first transverse joining edge area and the second transverse joiningedge area of the first component to overlap each other and forming abase fabric with the shape of a closed loop, attaching at least one battfiber layer to the base fabric with the shape of a closed loop, andattaching the joining edge areas undetachably to each other before theattachment of the batt fiber layer, and the method further comprising:forming at least one thinned joining edge area, where the density oftransverse yarns is smaller than in the other portions of the firstcomponent, arranging permeability in the overlapping joining edge areasto substantially correspond to that in the rest of the base fabric, andpressing the joining edge areas of the first component against eachother during the attachment by a predetermined force so that thethickness of the overlapping joining edge areas substantiallycorresponds to the thickness of the rest of the first component.
 2. Amethod according to claim 1, comprising providing, when the firstcomponent is formed, at least one joining edge area of the componentwith a smaller density of transverse yarns than the rest of the firstcomponent.
 3. A method according to claim 1, comprising forming athinned first joining edge area and a second joining edge area in thefirst component.
 4. A method according to claim 1, comprising attachingthe overlapping joining edge areas to each other by welding.
 5. A methodaccording to claim 1, wherein the first planar component of the basefabric is manufactured by weaving and its width substantiallycorresponds to the width of the press felt.
 6. A method of manufacturinga press felt, the method comprising forming a base fabric comprising atleast one layer, wherein the at least one layer comprises at least afirst planar component, which is formed from a plurality of longitudinalyarns that travel in the machine direction and from transverse yarnsthat travel in the cross machine direction, and the first component isprovided with a first transverse joining edge area and a secondtransverse joining edge area, arranging the first transverse joiningedge area and the second transverse joining edge area of the firstcomponent to overlap each other and forming a base fabric with the shapeof a closed loop, attaching at least one batt fiber layer to the basefabric with the shape of a closed loop, and attaching the joining edgeareas undetachably to each other before the attachment of the batt fiberlayer, and the method further comprising forming at least one thinnedjoining edge area, where the density of transverse yarns is smaller thanin the other portions of the first component, arranging permeability inthe overlapping joining edge areas to substantially correspond to thatin the rest of the base fabric, pressing the joining edge areas of thefirst component against each other during the attachment by apredetermined force so that the thickness of the overlapping joiningedge areas substantially corresponds to the thickness of the rest of thefirst component, and forming at least a second component with the shapeof a closed loop, arranging the first component on top of the secondcomponent, and connecting the joining edge areas of the first componentwith an overlapping joint.
 7. A press felt for a paper machine presssection, the press felt comprising: a base fabric comprising at leastone layer, which comprises a plurality of longitudinal yarns that travelin the machine direction and a plurality of transverse yams that travelin the cross machine direction and wherein the at least one layercomprises at least a first planar component, which includes a firsttransverse joining edge area and a second transverse joining edge areaand where the joining edge areas have been connected to each other; andat least one batt fiber layer, and wherein the first joining edge areaand the second joining edge area of the first component have beenarranged to overlap each other, the joining edge areas have beenattached to each other undetachably before the attachment of the battfiber layer, the density of transverse yarns is smaller at least in onejoining edge area of the first component than in the rest of the firstcomponent, the joining edge areas of the first component have beenpressed against each other, the thickness of the overlapping joiningedge areas substantially corresponds to the thickness of the rest of thefirst component, and the permeability in the overlapping joining edgeareas substantially corresponds to the permeability of the rest of thebase fabric.
 8. A base fabric for a press felt, comprising: a pluralityof longitudinal yarns that travel in the machine direction; a pluralityof transverse yarns that travel in the cross machine direction; at leasta first planar component in at least one layer of the base fabric, andthe first component comprises at least a first transverse joining edgearea and a second transverse joining edge area, and where the joiningedge areas have been connected to each other, and where the firstjoining edge area and the second joining edge area of the firstcomponent have been arranged to overlap each other; the joining edgeareas have been attached to each other undetachably, and wherein atleast one joining edge area of the first component has a smaller densityof transverse yarns than the rest of the first component, the joiningedge areas of the first component have been pressed against each other,the thickness of the overlapping joining edge areas substantiallycorresponds to the thickness of the rest of the first component, and thepermeability in the overlapping joining edge areas substantiallycorresponds to the permeability of the rest of the base fabric.
 9. Abase fabric according to claim 8, wherein the joining edge areas of thefirst component are attached to each other by welding.
 10. A press feltfor a paper machine press section, the press felt comprising: a basefabric, which comprises a plurality of longitudinal yams that travel inthe machine direction and a plurality of transverse yarns that travel inthe cross machine direction and whose at least one layer comprises atleast a first planar component, which includes a first transversejoining edge area and a second transverse joining edge area and wherethe joining edge areas have been connected to each other; and at leastone batt fiber layer, and wherein the first joining edge area and thesecond joining edge area of the first component have been arranged tooverlap each other, the joining edge areas have been attached to eachother undetachably before the attachment of the batt fiber layer, thedensity of transverse yarns is smaller at least in one joining edge areaof the first component than in the rest of the first component, thejoining edge areas of the first component have been pressed against eachother, the thickness of the overlapping joining edge areas substantiallycorresponds to the thickness of the rest of the first component, thepermeability in the overlapping joining edge areas substantiallycorresponds to the permeability of the rest of the base fabric, andwherein the base fabric further comprises a second component having ashape of a closed loop, and wherein the first component is located ontop of the second component.
 11. A base fabric for a press felt,comprising: a plurality of longitudinal yarns that travel in the machinedirection; a plurality of transverse yarns that travel in the crossmachine direction; at least a first planar component in at least onelayer of the base fabric, and the first component comprises at least afirst transverse joining edge area and a second transverse joining edgearea, and where the joining edge areas have been connected to eachother, and where the first joining edge area and the second joining edgearea of the first component have been arranged to overlap each other;the joining edge areas have been attached to each other undetachably,and wherein at least one joining edge area of the first component has asmaller density of transverse yarns than the rest of the firstcomponent, the joining edge areas of the first component have beenpressed against each other, the thickness of the overlapping joiningedge areas substantially corresponds to the thickness of the rest of thefirst component, the permeability in the overlapping joining edge areassubstantially corresponds to the permeability of the rest of the basefabric, and wherein the base fabric further comprises a second componenthaving a shape of a closed loop, and wherein the first component islocated on top of the second component.
 12. A method of manufacturing apress felt, the method comprising: forming a base fabric comprising atleast one layer, wherein the at least one layer comprises at least afirst planar component, which is formed from a plurality of longitudinalyarns that travel in the machine direction and from transverse yarnsthat travel in the cross machine direction, and the first component isprovided with a first transverse joining edge area and a secondtransverse joining edge area, arranging the first transverse joiningedge area and the second transverse joining edge area of the firstcomponent to overlap each other and forming a base fabric with the shapeof a closed loop, attaching at least one batt fiber layer to the basefabric with the shape of a closed loop, and attaching the joining edgeareas undetachably to each other before the attachment of the batt fiberlayer, and the method further comprising: forming at least one thinnedjoining edge area, where the density of transverse yarns is smaller thanin the other portions of the first component, removing transverse yarnsfrom at least one joining edge area of the first component from aportion having a length of between 5 and 20 mm, arranging permeabilityin the overlapping joining edge areas to substantially correspond tothat in the rest of the base fabric, and pressing the joining edge areasof the first component against each other during the attachment by apredetermined force so that the thickness of the overlapping joiningedge areas substantially corresponds to the thickness of the rest of thefirst component.
 13. A method of manufacturing a press felt, the methodcomprising: forming a base fabric comprising at least one layer, whereinthe at least one layer comprises at least a first planar component,which is formed from a plurality of longitudinal yarns that travel inthe machine direction and from transverse yarns that travel in the crossmachine direction, and the first component is provided with a firsttransverse joining edge area and a second transverse joining edge area,arranging the first transverse joining edge area and the secondtransverse joining edge area of the first component to overlap eachother and forming a base fabric with the shape of a closed loop,providing at least the portion of the overlapping joining edge areaswith an attachment area, where the joining edge areas are attached toeach other undetachably, and making the boundary surface between theattachment area and the rest of the first component non-linear,attaching at least one batt fiber layer to the base fabric with theshape of a closed loop, and attaching the joining edge areasundetachably to each other before the attachment of the batt fiberlayer, and the method further comprising: forming at least one thinnedjoining edge area, where the density of transverse yarns is smaller thanin the other portions of the first component, arranging permeability inthe overlapping joining edge areas to substantially correspond to thatin the rest of the base fabric, and pressing the joining edge areas ofthe first component against each other during the attachment by apredetermined force so that the thickness of the overlapping joiningedge areas substantially corresponds to the thickness of the rest of thefirst component.
 14. A method of manufacturing a press felt, the methodcomprising: forming a base fabric comprising at least one layer, whereinthe at least one layer comprises at least a first planar component,which is formed from a plurality of longitudinal yarns that travel inthe machine direction and from transverse yarns that travel in the crossmachine direction, and the first component is provided with a firsttransverse joining edge area and a second transverse joining edge area,arranging the first transverse joining edge area and the secondtransverse joining edge area of the first component to overlap eachother and forming a base fabric with the shape of a closed loop,providing at least the portion of the overlapping joining edge areaswith an attachment area, where the joining edge areas are attached toeach other undetachably, and providing the attachment area with severalattachment points, which form a pattern that imitates the pattern of thebase fabric surface, attaching at least one batt fiber layer to the basefabric with the shape of a closed loop, and attaching the joining edgeareas undetachably to each other before the attachment of the batt fiberlayer, and the method further comprising: forming at least one thinnedjoining edge area, where the density of transverse yarns is smaller thanin the other portions of the first component, arranging permeability inthe overlapping joining edge areas to substantially correspond to thatin the rest of the base fabric, and pressing the joining edge areas ofthe first component against each other during the attachment by apredetermined force so that the thickness of the overlapping joiningedge areas substantially corresponds to the thickness of the rest of thefirst component.
 15. A press felt for a paper machine press section, thepress felt comprising: a base fabric comprising at least one layer,which comprises a plurality of longitudinal yarns that travel in themachine direction and a plurality of transverse yarns that travel in thecross machine direction and wherein the at least one layer comprises atleast a first planar component, which includes a first transversejoining edge area and a second transverse joining edge area and wherethe joining edge areas have been connected to each other; and at leastone batt fiber layer, and wherein the first joining edge area and thesecond joining edge area of the first component have been arranged tooverlap each other, the joining edge areas have been attached to eachother undetachably before the attachment of the batt fiber layer, thedensity of transverse yarns is smaller at least in one joining edge areaof the first component than in the rest of the first component,transverse yarns are removed from at least one joining edge area of thefirst component from a portion having a length of between 5 and 20 mm,the joining edge areas of the first component have been pressed againsteach other, the thickness of the overlapping joining edge areassubstantially corresponds to the thickness of the rest of the firstcomponent, and the permeability in the overlapping joining edge areassubstantially corresponds to the permeability of the rest of the basefabric.
 16. A press felt according to claim 15, wherein at least onejoining edge area of the first component is provided with a smallerdensity of transverse yarns than the rest of the first component duringthe manufacture.
 17. A press felt according to claim 15, wherein thejoining edge areas of the first component have been attached to eachother by welding.
 18. A press felt according to claim 15, wherein thewidth of the overlapping area of the joining edge areas of the firstcomponent is 5 to 20 mm in the machine direction.